Excavator



Feb. 8, 1938. H. LUNDSTROM EXCAVATOR Filed June 15, 1936 3 Sheets-Sheet l I //YL//YTOB HANS Lurwsmom A rroe/vs v Feb. 8, 1938. H. LUNDSTROM I 2,107,895

EXCAVATOR Filed June 15, 1936 3 Sheets-Sheet 2 Mme-fire)? H ANS LUNPSTROM Feb. 8, 1938. H. LUNDSTROM EXCAVATOR Filed June 15 1936 s sheets-sheet 5 OLLL ATTORNEY /m '/Yr02 HANS Lu nosrlaom Patented Feb. 1938 EXOAVAIOR Hans Lundstrom, St. Louis, Mo., usignor of twothlrds to Ida. Lundstrom, and one-third to 'JosephMag idsonahd Phelix B. Magidson, all

, of St. Louis, Mo.

Application June 15, 1936, Serial No. 85,284

Claims. (01. 214-138) invention relates broadly, to excavators, of "thetype used by road builders, building contractors, and many others, andwell known, and has v among its objects the production of such excavators that will be especially adaptable to and capable of a maximum number of uses, which is easily constructed and operated, speedy and simple in f operation and construction, economical, and

otherwise satisfactory and 'emcient for use whereever deemed applicable. I

The invention hasnamong' its objects, to pro- I duce an excavator having a dipper and a carrying' boomtherefor, the boombein'g telescopic in constructionand action, and the dipper being operably connected to both the fixed and movable parts of said telescopic boom, in such a way that said dipper will have amaximumv digging radius, enablebetter'and easier dumping, and permit of very close jack-'kniiing of the dipper against said .boom. I

I The invention hasanother object, to provide a dipper 'so mounted to said telescopic boom-that when the excavatoris not in use, it will provide greater stability and minimize any overturning tendencyof the excavator, while .at' the same time permitting the mechanism tobe of minimum height to'permit of digging in places of low overhead clearance and to more easily transport the entire mechanism. 4

.A further object of my invention is to provide means for easily and readily mounting and remounting the dipper from the boom, to permit the arnovel latch for the dippen-whereby the latter dipper to be reversed so as to dig in either forward or backward direction, as required, and thereby provide for maximum-useof said device.

x-An added object of the invention is to provide I may be securely held-in latched position against videmeans automatically operated during the accidental dumping and yet may be readily,

easily and conveniently dumpedwhen required.

A still further objectof the'invention is to prousual dumping and closing of the dipper, to clean "and scrape the interior of the'latter, thereby obviating the necessity of frequent manual cleaning,

and hence increasing the effective carrying load 0 operation will be sturdy, even and eflective.

Many other objects and advantages of the. con,- struction-herein shown and described will be obv ious to those skilled in the art to whichthis invention appertains, from the disclosures herein given.

To this end, my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and uses men- 5 tioned, as will be more clearly pointed out in the claims hereunto appended.

Inthedrawings, wherein like reference'charac- ,ters indicate like or corresponding parts throughout the drawings,

Figure 1 is'a side elevation of my improved excavator, as used for forward digging;

Figure 2 is a similar view of the same, but showing .the: dipper reversed, as usedfor back digging;

. Figure 3 is a top plan view of the mechanism 15 showninFig.1;

Figure 4 is a longitudinal cross-sectional detail of the dipper;

Figure 5 is a transverse cross-sectional detail of the boom parts, taken substantially on, the line 30 8-5 of Fig. 3; and

Figure 6 is atop plan view of the device shown m Fig, 2,'-

Referring more ,particularly to the drawings, wherein I have illustrated a preferred embodiment 25 of my invention, only a fragment of the cab, machinery deck or machine A is indicated, the same being of any desired or suitable construction, and generally portable, as by means of the endless conveyor I, so that it may be moved from place-to 30 place as required. The deck is also generally completely rotatable so that a maximum of digging range may be had from each setting of the machine. indicates the gantry or other forward part of the deck, and to which the pulleys, sheaves, or other operating line carriers may be mounted.

Instead of having a boom of fixed length on the forward end of the machine, and to which is fixed a vertically ,movable dipper stick carrying a bucket, dipper or other digging element at its low- 0 er end, I have provided an entirely novel and functionally diii'erentstructure, as will now be de I The boom member that I employ is of telescopic construction, composed of a pair of longitudinally extensible and contractile elements relatively of one another, the relatively stationary element 3 being pivoted or' otherwise hinged at one end to the forward end of said machine, so as to be movly, relatively of said machine, Fig. 2 illustrating I use as a back-digger, while the other views show its use as a forward digger. v

This dipper may be of any suitable size and shape, as for example, composed of a pair of opposed side walls 1-! extending substantially vertically, a rear wall or back 8, and an end wall 9, the rear and end walls cooperating in a movable manner, as will be more clearly hereinafter set forth.- Teeth 30 maybe fixed to the dipper at its open side, if desired.

Said dipper is movably connected to both of the boom elements, there being a pivot pin In between the opposed sides of the dipper, for pivotal engagement through the forward ends of a pair of links lll i, each of said links being pivoted at its rear end to said upwardly extending projection; 1-4 of the stationary boom ele-- ment, the axis of said pin it being substantially in the transverse median plane through said dipper.

A pair of pin-receiving apertures 12 and I3 are provided through the side walls of said dipper to either side of and substantially like distances below the apertures for receiving said pin in, the

- apertures l2 and I! being closely adjacent the bounding edges of the front and rear of said dipper, so that either the set of apertures I! or l3 may be used selectively, for mounting the dipper for forward or backward digging, as desired.

Assuming that it is desired to mount the dipper for forward digging, as shown in all the draw-- ings, but Fig. 2, then said dipperis pivoted at III to the forward end of said links ll-ll, and a pin it pivotally interconnects the-downturned projections of the movable boom with said dipper through the pin openings I2. Obviously, in order that the dipper may be conveniently, easily and practically reversed from time to time, for either backward or forward diggi said'pins are preferably removably or detachably inserted into place. a I

For operating the movable part of the boomin its necessary direction to enable the ipper to fill in digging, I provide a control 3 :e L, one end of which is dead-ended at I! to an axle l6 removably connected to the upper ends of the side walls of the dipper and carrying a pair of sheaves II-I'l, said line their being threaded through said sheaves and gantry and around a loose pulley I8 adjacent the rear end of said movable boom element, the other end of said line leading into the machine, so that operation of this last-mentioned line end at the machine will actuate the movable boom element forwardly, while at the same time actuating the dipper'in its digging, it being especially noted that when the dipper is at its rearmost position, as shown in dotted lines in Fig. 1, said links are substantially-parallel with the down-turned and forwardly projecting ends 6-6 of the fixed boom element, thus permitting the dipper to be brought up very close under the boom, or closely jack-knife, so that it is possible to commence the the digging radius of the excavations over and beyond that normally obtainable in digging operations. i

When it is desired to retrieve-the dipper, after dumping in a manner to be hereinafter described, a pull line P having its rear end leading into the machine and its forward end connect- The dipper preferably has its end and rear walls movable relatively of one another and. of

the fixed side walls 1-1, so as to open the dipper for dumping and re-closing it thereafter, the control means for said movable walls not only causing said opening and closing movements, but in addition making the dipper self-cleaning. This self-cleaning feature is especially important, not only in making for easier and more efllclent operation of the dipper itself, but by increasing the effective load-carrying capacity of the dipper. The dipper is cleaned at each dumping operation, thereby obviating the necessity of manual cleaning of the same.

The end wall 9 is pivoted at its forward edge to said pair of sidewalls |-'|,-and' the rear wall is provided with a pair of inturned flanges 38, 38 of a height increasing from a. point adjacent its lower end toone' adjacent its upper end, said flanges being cioselyadjacent and substantially parallel to the inside surfaces of said side walls. Said rear wall is pivoted intermediate its top and bottom to said pair of side walls. as at I9, and a pair of link plates 20 -20 operably link said end and rear walls together,: each of said link plates being interposed betweensaid side walls and inturned flanges, and being pivotally connected at one end to one of said flanges, as at 39 and at its other end tosaid end wall of the dipper, as at 40. Consequentlmlthe opening and closing of the dipper will cause the link plates to substantially scrape the side walls. and cause the inturned flanges to substantially scrape'said links.

The latch means has a finger 2| pivoted to the lower end of the rear of the dipper and-movable up against the under side of the-rear edge of said end wall of the dipper, to hold said end and rear walls in closed position when said finger is thus retained in place. A bell-crank 221s pivoted to the upperend of said movable rear wall 8,

a link 23 interconnecting said bell-crank with said finger 2| to actuate the two in unison, a spring 24. normally pressing said link inthe direction to release or unlatch said finger.-

An offset 25 is fixed to the upper end of the rear .wall of the dipper and recessed to receive said movable bell crank 22, said oifset 25 bear.-

. ing against a stop 26 carried by a stationary part of the dipper, near the top of the'latter, said stop being spring-pressed to normally abut the said ofi'setwhen the dipper is closed, but being liftaHe to permit said offset to passsaid stop when desired. Cam means 21 is also carried by said part of the dipper and controlledby a trip line 28 leading to the machine. so that actuation of said trip means through the line ll moves said cam to lift said stop and 9 1 1 the load in the dipper to move the rear and'end walls to open position, the onset and bell crank passing said stop to permit" this action.

After dumping, a pull on the line P will first actuate the open walls to closed position and reset the latch, and continued pull will retrieve thedipper to next digging position. In order to accomplish this result, the forward end of the line P may be loosely threaded through an eye I secured to the movable wall 8 a short distance above the pivotal axis i8, before being secured to said pivotal axis. Hence, after the dipper has been tripped, and the rear wall is in the position shown in dotted lines in Fig. 4, a pull on the rope P will pull the rear wall at the eye-bolt, tending to turn the rear wall about said'pivotal axis i9, and closing the dipper;

Thus, it is seen that by actuating they control line L will telescopically extend the overall length of the boom, while at the same time pivoting the dipper about both of its pivotal connections to the boom elements, until the end of the cutting or digging stroke, whereupon the dipper may then be directed in proper position for dumping its load, said dumping being rapidly accomplished by a pull on the trip line 28 to release the dipper latch, whereupon the load itself will spread the movable walls of the dipper to permit such discharge of load. The retrieving line P is now pulled, the initial pull re-latching the dipper, and

' further pull swinging the dipper back to its origisomewhat as shown in Fig. 2.

nal position for the next dig forwardly.

For many digging operatiiit'ns it is desirable that the dipper be actuated toward the machine or backwardly to fill, and in my device it-is quite easy I to change the dipper so that it may dig either forwardly or backwardly, this change being effected simply through the removal of several pivotal connections holding the dipper in place, and then replacing said pivotal connections in a manner now to be explained further.

To assemble the dipper for back-digging, after its use as a forward digger, the three pivotal connections III, M, and ii are temporarily removed,

and the dipper then turned so that its teeth extend in the reverse direction, namely rearwardly,

after which the pivotal connections II and ii are replaced into their positions from which they were removed, and the other pin, I4, is placed through the now adjacent pair of apertures i 3. In this po- 5 sition of the dipper, the line" maybe slightly rearranged so as to continue to be controlled from the machine as heretofore, as for example, by extending forwardly and thence down over the pin I0 for connection to the cam control of the latch,

The pull line P now leads to the open side of the dipper and is freeof the latch means. In this back-digging position of the dipper, the latch trip j or release is through the line 28 as previously mentioned, but the resetting of the latch may be automatically accomplished, as by thethreading of a line T about a loose pulley 29 mounted on the forward end of the stationary boom element, one end of said line being dead-ended adjacent to and on the forward end of the movable boom element, and the other end being dead-ended to the upper portion of 'the rear wall of the dipper. Hence, after the dipper has been dumped, and the dipper and movable boom element are actuated back to their initial digging position (and which in this instance is of course farthermost from the machine), the line T willbecome taut, its length being such that it will just accommodate theopening of said dipper, and bring said movable walls to their closed position for the next dig.

Even in this position of the dipper for backward digging, there is an unusually large digging radius, on account ofthe fact that the dipper may be brought up very close under the boom, said dipper being connected directly to the boom and not through the usual intermediary of a dipper stick.

Having thus described my invention, it is obvious immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do'not wish to be understood as limiting myself to the exact form, arrangement, construction and combination of parts herein shown and described, or the uses claimed, except as limited by the state of the art to which this invention appertains and the claims hereunto appended.

'What I "claim as new and desire to secureby Letters Patent is:

1. In an excavating machine, a pair of relatively movable boom members, a reversible dipper, .a link having one end pivoted to the end of one of said boom members and the other end pivoted detachably to said dipper, and means forpivotal- 1y connecting the adjacent end of the other boom member selectively to said dipper at a pair of spaced points beneath the pivoting point of the dipper and link, whereby said dipper may be reversed to dig either forwardly or backwardly.

2. In an excavating machine, a pair of rela-' dipper to actuate them in unison from said machine.

3. In an excavating machine, a pairqpf relatively movable boom members,-a dipper, a link pivoted at one end to the end of one of said boom members and at the other end to said dipper, and means for detachably pivotally interconnecting the end of the other of said boom members to said dipper selectively at either of a pair of spaced points beneath and substantially equidistant from the pivotal point of said link and dipper and to either side of said point, whereby said dipper may be used for digging either forwardly or backwardly relatively of said machine.

4. In an excavating machine, a boom pivoted for up and down movement, a dipper connected to said boom and having an end wall and a rear wall movably interconnected to open and close in unison, a latch maintaining said end and rear walls closed, a latch stop carried by a fixed part of said dipper, and a cam operable from said machine to move said stop from its normal looking position with said latch to permit releasing movement of said latch.

5. In an excavating machine dipper, an end wall and a rear wall movable in unison to open or close, and link plates interconnecting said walls and moving in a plane substantially parallel to said side walls to wipe excess material from said side walls of the dipper upon movement of said movable walls.

6. In an excavating dipper, fixed side walls, an endwall and a rear wall pivoted to said side walls to move in unison to open or closed position, link plates pivotally interconnecting said rear and jacent and parallel to said side walls to scrape excess material from said side walls of the dipper upon movement of said end and rear walls relatively of said side walls.

7. In excavating machines, a dipper having fixed side walls and a movable end wall and rear wall, inturnedflanges on said rear wall in a plane substantially parallel to said side walls, and link plates at either side of said dipper, interconnecting said'end and rear walls and movable in a plane between said flanges and side wall so that said link plates and flanges wipe adjacent surfaces during opening and closing movement of the dipper.

8. In an excavating machine dipper, fixed side walls, an end wall and a rear wall movable relatively thereto to open or close said dipper, and means for interconnecting said movable walls so that said movement cleans them of excess material and comprising flanges carried by said rear wall in a plane adjacent and parallel to the side walls and extending from substantially the bottom of the inside of said dipper to adjacent the inside of the top of the same, and link plates at either side of said dipper beween said flanges and side wall and interconnecting said end wall and rear wall so that said links wipe said side walls and said flanges wipe said link plates during opening and closing movements of said dipper.

. 9. In an excavating machine, a boom, a dipper, and means for pivotally connecting said boom to either of a pair of spaced pivotal points selectively on said dipper, whereby the latter may be removably reversed to dig either forwardly or backwardly relatively of said boom.

10; In an excavating machine, a boom, a bucket having a plurality of pivotal points spaced transversely intermediate its front and rear, and means for pivotally removably connecting said boom to said bucket at one of said points for forward digging and to the other of said points for reverse digging- HANS LUNDSTROM. 

